<template>
    <div class="list" ref='wrapper'>
       <div>
            <div class="area">
                <div class="title border-topbottom">热门城市</div>
                <div class="button-list">
                    <div class="button-wrapper">
                        <div class="button">{{this.currentCity}}</div>
                    </div>
                </div>
            </div>
            <div class="area">
                <div class="title border-topbottom">当前城市</div>
                <!-- vuex数据同时改变，给每个城市添加点击事件 -->
                <div class="button-list">
                    <div 
                        class="button-wrapper" 
                        v-for="item of hot" 
                        :key='item.id' 
                        v-on:click="handleCityClick(item.name)"
                    >
                        <div class="button">{{item.name}}</div>
                    </div>
                </div>
            </div>
            <!-- 循环object对象，双层for循环 -->
            <div class="area" v-for='(item, key) of cities' :key='key' :ref='key'>
                <div class="title border-topbottom">{{key}}</div>
                <div class="item-list">
                    <div 
                        class="item border-bottom" 
                        v-for="innerItem of item" 
                        :key='innerItem.id'
                        v-on:click="handleCityClick(innerItem.name)"
                    >
                        {{innerItem.name}}
                    </div>               
                </div>
            </div>
       </div>
    </div>
</template>
<script>
import Bscroll from 'better-scroll'
import { mapState, mapMutations } from 'vuex'

export default {
    name: 'CityList',
    props: {
        hot: Array,
        cities: Object,
        // 子组件接收父组件传值，对父组件传递过来的值，进行校验
        letter: String
    },
    computed: {
        ...mapState({
            currentCity: 'city'
        })
    },
    // 城市点击事件方法
    methods: {
        // 传入的是city
        handleCityClick (city) {
            // alert(city)
            // C.dispatch（派发）
            // this.$store.dispatch('changeCity', city)
            // this.$store.commit('changeCity', city)
            this.changeCity(city)
            this.$router.push('/')

        },
        ...mapMutations(['changeCity'])
    },
    // 将Bscroll实例挂载
    mounted() {
        this.scroll = new Bscroll(this.$refs.wrapper)
    },
    // 侦听器:获取到值的变化
    watch: {
        letter(){
            // console.log(this.letter);
            // vue自带滚动方法
            // 如果你传入的是A，那就把A显示出来，如果你显示的是B，那就把B显示出来
            if(this.letter){
                // 获取到dom节点元素  这样获得是一个数组
                const element = this.$refs[this.letter][0]
                // console.log(element)
                this.scroll.scrollToElement(element)
            }
        }
    }
}
</script>

<style lang='stylus' scoped>
    @import '~styles/varibles.styl'
    .border-topbottom
        &:before
            border-color #ccc
        &:after
            border-color #ccc
    .border-bottom
        &:after
            border-color #666
    .list 
        overflow hidden
        position absolute
        top 1.76rem
        left 0
        right 0
        bottom 0         
        .title
            line-height .44rem
            background #eeeeee
            padding-left .2rem
            color #666
            font-size .26rem
        .button-list
            overflow hidden
            padding .1rem .6rem .1rem .1rem
            .button-wrapper
                float left 
                width 33.33%
                .button
                    margin .1rem
                    padding .1rem
                    text-align center
                    border .02rem solid #ccc
                    border-radius .06rem
        .item-list
            .item
                line-height .76rem
                color #666
                padding-left .2rem

</style>


